import 'package:flutter/material.dart';

void main() {
  runApp(MaterialApp(
      home: Scaffold(
    appBar: AppBar(
      title: const Text("你好flutter"),
    ),
    body: const MyApp(),
  )));
}

class MyApp extends StatelessWidget {
  const MyApp({super.key});
  @override
  Widget build(BuildContext context) {
    return Container(
      width: double.infinity,
      height: 400,
      color: Colors.grey,
      child: const Align(
        alignment: Alignment(0.5, 0.5),
        child: Text("hello world"),
      ),
    );
  }
}
